The First Photometric Analysis of Two Low Mass Ratio Totally Eclipsing Contact Binaries: TIC 393943031 and TIC 89428764

Abstract

Photometric analysis of the contact binaries TIC 393943031 and TIC 89428764 was carried out using Transiting Exoplanet Survey Satellite and SuperWASP data for the first time. Using the Wilson–Devinney code, we have found that TIC 393943031 is a low-mass-ratio deep contact binary with a fillout factor of 50.9(±1)% and a mass ratio of q = 0.163 ± 0.001. TIC 89428764 is a medium and low-mass-ratio contact binary with a fillout factor of 34.5(±1)% and a mass ratio of q = 0.147 ± 0.001. Furthermore, the period study reveals both the stars exhibit continuously increasing periods, the increasing rate is 4.21 × 10−7 day yr−1 for TIC 393943031 while 6.36 × 10−7 day yr−1 for TIC 89428764. The possible reason is mass transfer from the secondary component to the primary component for both stars. Meanwhile, we discussed their evolutionary phases and orbital angular momenta.